class_docstr: Softmax activation function.
class_docstr_tok: ["Softmax","activation","function","."]
code: def backward(self, indexes, grad_outputs):
      y = self.get_retained_outputs()[0]
      (gy,) = grad_outputs
      return _SoftmaxGrad(self.axis).apply((y, gy))
  
file_path: chainer/chainer/functions/activation/softmax.py
imports: import chainer
  from chainer import backend
  from chainer.backends import cuda
  from chainer import function_node
  import chainer.functions
  from chainer.utils import type_check
label_desc: Use image node_id 4 for calling the Softmax obj's underlying member method code with example usage: obj.backward(indexes, grad_outputs) and returns: _SoftmaxGrad